Problem: Nadia starts counting at 43, and she counts by fives. If 43 is the 1st number that Nadia counts. what is the 15th number that she counts?
Answer: What is the first number that she counts? $43$ What is the second number that she counts? $\begin{align*}&43 + 5 \\ &= 48\end{align*}$ What is the third number that she counts? $\begin{align*}&43 + 5 + 5 \\ &= 43 + (2 \times 5) \\ &= 53\end{align*}$ What is the 15th number that she counts? $\begin{align*}&43 + (14\times5) \\ &= 43 + 70 \\ &= 113\end{align*}$